This invention relates to improvements in a low-friction sliding member and a low-friction sliding mechanism using the sliding member, and more particularly to the low-friction sliding member and low-friction sliding mechanism using the sliding member, excellent in low-friction characteristics.
Global environmental problems such as global warming and ozone layer destruction are coming to the fore. As it has been said that the global warming is significantly affected by CO2 emission, the reduction of CO2 emission, notably the setting of CO2 emission standards, has become a big concern to each country. One of challenges to reduce CO2 emission is to lower an energy loss due to friction loss of machines, facilities and the like, particularly to improve vehicle fuel efficiency or fuel economy that depends on the performance of engine sliding members and a lubricating oil applied thereto. There are the following approaches to improve the vehicle fuel efficiency: (1) lowering the viscosity of the lubricating oil, thereby reducing viscous resistance in hydrodynamic lubrication regions and agitation resistance in the engine; and (2) adding a suitable friction modifier and other additives into the lubricating oil so as to reduce friction losses under the conditions of mixed lubrication and boundary lubrication.
In view of the foregoing, many studies have been made on various friction modifiers including organomolybdenum compounds, such as molybdenum dithiocarbamate (MoDTC) and molybdenum dithiophosphate (MoDTP). As a result of the studies, it has been found that the lubricating oil containing an organomolybdenum compound successfully provides a friction reducing effect on conventional steel sliding members in the early stages of use.